1. Field of the Invention
The present invention relates to an inner liner for a sport boot of the rigid shell type and to a liner, the top portion of the upper of which has a composite structure adapted to transmit the impulses from the user's lower leg towards the rigid shell, and vice-versa, in predetermined directions.
2. Description of Background and Relevant Information
Boots provided with inner liners of the aforementioned type are known particularly from European Patent Application No. 0 674 856 and French Patent Publication No. 2 722 662.
In the example of EP 0 674 856, a liner having a single foot entry is described for a ski boot, roller skate, or ice skate, and is provided on its upper with a reinforcement element that is attached and fixed to the exterior of its comfort wall. This reinforcement element extends along the upper edge of the top portion of the liner upper which covers the area of the heel and of the malleoli. A removable T-shaped piece, engaged under the reinforcement element and against the comfort wall of the liner, on which it is vertically adjustable, ensures the wedging of the malleoli and strengthens the upper edge of the top portion of the liner upper in its dorsal area due to a rigid extension with which it is provided and which extends above the upper edge. Because of these arrangements, the top portion of the liner upper has a composite structure formed of several layers, one of which at least provides an additional support to the user's lower leg so as to transmit the latter's impulses towards the rigid shell of the boot, and vice versa, in predetermined directions, oriented in the front-to-rear direction and partially lateral due to the reinforcement element and the rigid T-shaped piece.
Such a liner is found to be comfortable since the user's lower leg and foot are essentially in contact with the comfort wall of the liner upper which, presented as a single piece, plays the role of adjusting the fitting properties and of an interface together and the rigid shell via the reinforcement element with its T-shaped wedging piece.
Conversely, due to the fact that the reinforcement element is exterior to the comfort wall of the liner, the latter has the drawback of not providing a means capable of transmitting the impulses of the lower leg towards the rigid shell with a different intensity and/or speed in one or several predetermined particular directions. Indeed, due to the fact that it must systematically pass through the comfort wall to transmit the impulses, the user perceives the sensations and supports in a delayed and relatively vague manner since they are widely distributed in every direction through the comfort wall. Late and inaccurate reactions result from the user that do not allow optimizing the transmission of the impulses and the accurate control of the sport apparatuses, skis or skates, for example, that are attached to the boot. Further, in this liner, the rigid wedging piece is susceptible of being accidentally displaced between the reinforcement and the comfort wall, and therefore of modifying the user's lower leg supports on the top portion of the liner upper and the boot.
In the example of document FR 2 722 662, this type of drawback is solved but mainly for the transmission of forces and impulses oriented in lateral directions between the user's lower leg and the rigid shell of the boot and, in the context of a particular composite structure of the top portion of the upper having two foot entries, the one, anterior, for the front fitting and the other, posterior, for the rear fitting. More specifically, the top portion of the liner upper is formed of a front portion and a rear portion which are separated by two lateral openings where stiffening plates are extended which are at least partially covered by the openings.
Such a liner is found to be, on the one hand, very easy to put on due to the fact that the front and rear portions of the top portion of its upper are free to tilt frontwardly and rearwardly and, on the other hand, relatively efficient for transmitting the impulses to the boot in laterally oriented directions.
However, it has the drawback of penalizing the continuity of the wrapping of the top portion of its upper around the user's lower leg and, as a result, the comfort. Additionally, the front and rear portions, which are supposedly more comfortable than the stiffening plates, are susceptible of coming into contact with the foot and leg only at the extreme anterior and posterior zones of the latter since the portions cover the edges of tile plates. Moreover, these stiffening plates, which by definition are rigid, cover the malleolar region of tile fool where the relatively projecting articular apophyses must be particularly protected, in terms of the comfort and the adjustment to the foot morphology, which is in itself incompatible with the rigidity of these plates.
Finally, since the top portion of the upper of this type of liner is constituted of several components that are merely juxtaposed and formed of front and rear portions which are free with respect to the stiffening plates that they surround at least partially, it is relatively difficult to achieve the imperviousness of the liner upper.